President Obama’s chief of staff opened the door on Friday for a limited Senate climate bill that focuses on capping greenhouse gases from power plants.

Rahm Emanuel told the Wall Street Journal that “a whole range of ideas will be discussed” when Obama hosts senators at the White House next Wednesday, including placing a mandatory limit solely on the heat-trapping emissions from electric utilities.

“The idea of a ‘utilities only’ [approach] will also be welcomed,” Emanuel told the newspaper in an interview.

Kerry and Lieberman released legislation last month that would place limits on power plant emissions first, followed later by heavy industrial manufacturers and transportation fuels. But Reid on Wednesday said he too was willing to consider a less aggressive climate bill that narrowly targeted power plants. “At this stage I’m thinking about everything,” he said.

Power plants release about a third of the country's annual emissions of heat-trapping pollutants, and they have been involved for about 15 years in a similar market-based mechanism that has successfully reduced acid rain. Electric utility companies also the most threatened by the prospect of U.S. EPA regulations under the Clean Air Act.

Representatives from several power companies, including Constellation Energy and Duke Power Corp., have expressed an interest in legislation that focused solely on their industry’s emissions, especially if it appeared Congress couldn’t tackle the broader package that deals with transportation fuels and major industrial manufacturers.

Brian Wolff, senior vice president for external affairs at the Edison Electric Institute, the leading trade group for investor-owned utilities, said on Friday that his group would need to vet the idea of a more limited bill with its membership.

“We have not fully discussed utility only since we have been working on a more comprehensive climate approach,” he said. “However, we believe any utility only energy and climate legislation would have to include major consumer protections to gain 60 votes in the Senate. “

Back on Capitol Hill, the idea of a power plant only bill has been greeted with mixed reviews. GOP Sen. Olympia Snowe of Maine said she’s been urging Kerry and Lieberman to take this route for months. And Graham said he would encourage Congress to focus on utilities come 2011, after the political climate surrounding the Gulf of Mexico oil spill improves so that he can secure provisions that allow for more offshore drilling.

But two senators who have endorsed past versions of power plant-only climate legislation offered different perspectives on the issue on Thursday. "I know there’s been some talk, some discussion of that," said Sen. Tom Carper (D-Del.). "But I think the effort should be to go more broadly than that if we can."

"That'll be difficult to do in this climate," said Sen. Judd Gregg (R-N.H.). Instead, Gregg urged the Senate to consider legislation that just focused on promoting alternative forms of energy minus carbon limits.

"An energy-only bill is a great idea," he said. "It'd do a lot to clean the climate and get the energy situation under control.